Search & Filtering
A principle section of calcite crystal cut always in parallelograms with angles ______.
a) A driver was speeding with 40 m/s in his 1800 kg car when he notices a police car with a radar and slows down to a legal speed of 19 m/s. What is the change of the kinetic energy of the car? What is the amount of work done on the car during the deceleration?
b) A repairman of mass 80 kg climbed a 10 m vertical latter to reach the roof of a building in 12 seconds. What is the power developed by the man against gravity?
A hockey puck lies still on ice. Another hockey puck is hit and is on course of collision with it with an initial velocity of +v. The pucks have the same mass and have glue around their edges. Neglect friction with ice. Predict the velocity that the puck which was initially at rest will have after collision, knowing that the pucks will stick together:
a) –v
b) +v
c) –v/2
d) +v/2
A squash ball hits a wall with an initial speed of u and it rebounds in the opposite direction with speed v. Knowing that some energy has been lost through heat in the collision so that v < u and that the duration of the collision is t, find the magnitude of the average force exerted by the wall on the ball.
a) F = m(u+v)/t
b) f = m(u-v)/t
c) F = 0
d) F = m(2v-u)/t
A box rests on a surface that is lifted by one end to create a larger and larger angle with the horizontal. When the surface reaches an angle of exactly 30 degrees with the horizontal, the box begins to slide down. What is the coefficient of static friction?
a) μs = 1/√ 3
b) μs = 2/√ 3
c) μs = √ 3
d) μs = 0.5
A square cost of resistance 4ohm ,50 turns and side length 5cm is places with it's plane making on amgle of 40° with a uniform field 2T.In 4.5 s the coil rotates until it's plane becomes parallel to the.magnetic field.Find the current induced in the coil.
A magnetic field of 3.2T is perpendicular to a square coil of 12 turns.The length of each side of the coil is 9cm.Find the magnetic flux through the coil if the magnetic field makes an angle of 30° with the normal to the plane of the coil.
The waves on a string have wave speed 8.00m/s, amplitude 0.0600m, and wavelength
0.400m. The waves travel in the -x direction and at t = 0s, the end of the string has its maximum
upward displacement.
(a) Write a wave function describing the wave and
(b). Find the transverse displacement of a particle at x = 0.350m at time t = 0.150s
A car changes its velocity from 20 m/s [N] to 20 m/s[S] in 5.5 s. If the mass of the car is 1500 kg,
what is the net force acting on it?
A sikorsky freight helicopter can easily lift a 5000 kg truck. If the acceleration of the truck is 1.5 m/s2 up, what is the net force being applied by the helicopter?
